clone: initialize atexit cleanup handler earlier
[git.git] / git-difftool.perl
blob18ca61e8d0493bde9c21ed337043bc72fa5c73a7
1 #!/usr/bin/perl
2 # Copyright (c) 2009, 2010 David Aguilar
3 # Copyright (c) 2012 Tim Henigan
5 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
6 # git-difftool--helper script.
8 # This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
9 # The GIT_DIFF* variables are exported for use by git-difftool--helper.
11 # Any arguments that are unknown to this script are forwarded to 'git diff'.
13 use 5.008;
14 use strict;
15 use warnings;
16 use Error qw(:try);
17 use File::Basename qw(dirname);
18 use File::Copy;
19 use File::Find;
20 use File::stat;
21 use File::Path qw(mkpath rmtree);
22 use File::Temp qw(tempdir);
23 use Getopt::Long qw(:config pass_through);
24 use Git;
26 sub usage
28 my $exitcode = shift;
29 print << 'USAGE';
30 usage: git difftool [-t|--tool=<tool>] [--tool-help]
31 [-x|--extcmd=<cmd>]
32 [-g|--gui] [--no-gui]
33 [--prompt] [-y|--no-prompt]
34 [-d|--dir-diff]
35 ['git diff' options]
36 USAGE
37 exit($exitcode);
40 sub find_worktree
42 # Git->repository->wc_path() does not honor changes to the working
43 # tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
44 # config variable.
45 return Git::command_oneline('rev-parse', '--show-toplevel');
48 sub print_tool_help
50 my $cmd = 'TOOL_MODE=diff';
51 $cmd .= ' && . "$(git --exec-path)/git-mergetool--lib"';
52 $cmd .= ' && show_tool_help';
54 # See the comment at the bottom of file_diff() for the reason behind
55 # using system() followed by exit() instead of exec().
56 my $rc = system('sh', '-c', $cmd);
57 exit($rc | ($rc >> 8));
60 sub exit_cleanup
62 my ($tmpdir, $status) = @_;
63 my $errno = $!;
64 rmtree($tmpdir);
65 if ($status and $errno) {
66 my ($package, $file, $line) = caller();
67 warn "$file line $line: $errno\n";
69 exit($status | ($status >> 8));
72 sub use_wt_file
74 my ($repo, $workdir, $file, $sha1) = @_;
75 my $null_sha1 = '0' x 40;
77 if (! -e "$workdir/$file") {
78 # If the file doesn't exist in the working tree, we cannot
79 # use it.
80 return (0, $null_sha1);
83 my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
84 my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
85 return ($use, $wt_sha1);
88 sub changed_files
90 my ($repo_path, $index, $worktree) = @_;
91 $ENV{GIT_INDEX_FILE} = $index;
92 $ENV{GIT_WORK_TREE} = $worktree;
93 my $must_unset_git_dir = 0;
94 if (not defined($ENV{GIT_DIR})) {
95 $must_unset_git_dir = 1;
96 $ENV{GIT_DIR} = $repo_path;
99 my @refreshargs = qw/update-index --really-refresh -q --unmerged/;
100 my @gitargs = qw/diff-files --name-only -z/;
101 try {
102 Git::command_oneline(@refreshargs);
103 } catch Git::Error::Command with {};
105 my $line = Git::command_oneline(@gitargs);
106 my @files;
107 if (defined $line) {
108 @files = split('\0', $line);
109 } else {
110 @files = ();
113 delete($ENV{GIT_INDEX_FILE});
114 delete($ENV{GIT_WORK_TREE});
115 delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
117 return map { $_ => 1 } @files;
120 sub setup_dir_diff
122 my ($repo, $workdir, $symlinks) = @_;
124 # Run the diff; exit immediately if no diff found
125 # 'Repository' and 'WorkingCopy' must be explicitly set to insure that
126 # if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
127 # by Git->repository->command*.
128 my $repo_path = $repo->repo_path();
129 my %repo_args = (Repository => $repo_path, WorkingCopy => $workdir);
130 my $diffrepo = Git->repository(%repo_args);
132 my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
133 my $diffrtn = $diffrepo->command_oneline(@gitargs);
134 exit(0) unless defined($diffrtn);
136 # Build index info for left and right sides of the diff
137 my $submodule_mode = '160000';
138 my $symlink_mode = '120000';
139 my $null_mode = '0' x 6;
140 my $null_sha1 = '0' x 40;
141 my $lindex = '';
142 my $rindex = '';
143 my $wtindex = '';
144 my %submodule;
145 my %symlink;
146 my @working_tree = ();
147 my @rawdiff = split('\0', $diffrtn);
149 my $i = 0;
150 while ($i < $#rawdiff) {
151 if ($rawdiff[$i] =~ /^::/) {
152 warn << 'EOF';
153 Combined diff formats ('-c' and '--cc') are not supported in
154 directory diff mode ('-d' and '--dir-diff').
156 exit(1);
159 my ($lmode, $rmode, $lsha1, $rsha1, $status) =
160 split(' ', substr($rawdiff[$i], 1));
161 my $src_path = $rawdiff[$i + 1];
162 my $dst_path;
164 if ($status =~ /^[CR]/) {
165 $dst_path = $rawdiff[$i + 2];
166 $i += 3;
167 } else {
168 $dst_path = $src_path;
169 $i += 2;
172 if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
173 $submodule{$src_path}{left} = $lsha1;
174 if ($lsha1 ne $rsha1) {
175 $submodule{$dst_path}{right} = $rsha1;
176 } else {
177 $submodule{$dst_path}{right} = "$rsha1-dirty";
179 next;
182 if ($lmode eq $symlink_mode) {
183 $symlink{$src_path}{left} =
184 $diffrepo->command_oneline('show', "$lsha1");
187 if ($rmode eq $symlink_mode) {
188 $symlink{$dst_path}{right} =
189 $diffrepo->command_oneline('show', "$rsha1");
192 if ($lmode ne $null_mode and $status !~ /^C/) {
193 $lindex .= "$lmode $lsha1\t$src_path\0";
196 if ($rmode ne $null_mode) {
197 my ($use, $wt_sha1) = use_wt_file($repo, $workdir,
198 $dst_path, $rsha1);
199 if ($use) {
200 push @working_tree, $dst_path;
201 $wtindex .= "$rmode $wt_sha1\t$dst_path\0";
202 } else {
203 $rindex .= "$rmode $rsha1\t$dst_path\0";
208 # Setup temp directories
209 my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
210 my $ldir = "$tmpdir/left";
211 my $rdir = "$tmpdir/right";
212 mkpath($ldir) or exit_cleanup($tmpdir, 1);
213 mkpath($rdir) or exit_cleanup($tmpdir, 1);
215 # If $GIT_DIR is not set prior to calling 'git update-index' and
216 # 'git checkout-index', then those commands will fail if difftool
217 # is called from a directory other than the repo root.
218 my $must_unset_git_dir = 0;
219 if (not defined($ENV{GIT_DIR})) {
220 $must_unset_git_dir = 1;
221 $ENV{GIT_DIR} = $repo_path;
224 # Populate the left and right directories based on each index file
225 my ($inpipe, $ctx);
226 $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
227 ($inpipe, $ctx) =
228 $repo->command_input_pipe(qw(update-index -z --index-info));
229 print($inpipe $lindex);
230 $repo->command_close_pipe($inpipe, $ctx);
232 my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
233 exit_cleanup($tmpdir, $rc) if $rc != 0;
235 $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
236 ($inpipe, $ctx) =
237 $repo->command_input_pipe(qw(update-index -z --index-info));
238 print($inpipe $rindex);
239 $repo->command_close_pipe($inpipe, $ctx);
241 $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
242 exit_cleanup($tmpdir, $rc) if $rc != 0;
244 $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
245 ($inpipe, $ctx) =
246 $repo->command_input_pipe(qw(update-index --info-only -z --index-info));
247 print($inpipe $wtindex);
248 $repo->command_close_pipe($inpipe, $ctx);
250 # If $GIT_DIR was explicitly set just for the update/checkout
251 # commands, then it should be unset before continuing.
252 delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
253 delete($ENV{GIT_INDEX_FILE});
255 # Changes in the working tree need special treatment since they are
256 # not part of the index. Remove any trailing slash from $workdir
257 # before starting to avoid double slashes in symlink targets.
258 $workdir =~ s|/$||;
259 for my $file (@working_tree) {
260 my $dir = dirname($file);
261 unless (-d "$rdir/$dir") {
262 mkpath("$rdir/$dir") or
263 exit_cleanup($tmpdir, 1);
265 if ($symlinks) {
266 symlink("$workdir/$file", "$rdir/$file") or
267 exit_cleanup($tmpdir, 1);
268 } else {
269 copy("$workdir/$file", "$rdir/$file") or
270 exit_cleanup($tmpdir, 1);
272 my $mode = stat("$workdir/$file")->mode;
273 chmod($mode, "$rdir/$file") or
274 exit_cleanup($tmpdir, 1);
278 # Changes to submodules require special treatment. This loop writes a
279 # temporary file to both the left and right directories to show the
280 # change in the recorded SHA1 for the submodule.
281 for my $path (keys %submodule) {
282 my $ok;
283 if (defined($submodule{$path}{left})) {
284 $ok = write_to_file("$ldir/$path",
285 "Subproject commit $submodule{$path}{left}");
287 if (defined($submodule{$path}{right})) {
288 $ok = write_to_file("$rdir/$path",
289 "Subproject commit $submodule{$path}{right}");
291 exit_cleanup($tmpdir, 1) if not $ok;
294 # Symbolic links require special treatment. The standard "git diff"
295 # shows only the link itself, not the contents of the link target.
296 # This loop replicates that behavior.
297 for my $path (keys %symlink) {
298 my $ok;
299 if (defined($symlink{$path}{left})) {
300 $ok = write_to_file("$ldir/$path",
301 $symlink{$path}{left});
303 if (defined($symlink{$path}{right})) {
304 $ok = write_to_file("$rdir/$path",
305 $symlink{$path}{right});
307 exit_cleanup($tmpdir, 1) if not $ok;
310 return ($ldir, $rdir, $tmpdir, @working_tree);
313 sub write_to_file
315 my $path = shift;
316 my $value = shift;
318 # Make sure the path to the file exists
319 my $dir = dirname($path);
320 unless (-d "$dir") {
321 mkpath("$dir") or return 0;
324 # If the file already exists in that location, delete it. This
325 # is required in the case of symbolic links.
326 unlink($path);
328 open(my $fh, '>', $path) or return 0;
329 print($fh $value);
330 close($fh);
332 return 1;
335 sub main
337 # parse command-line options. all unrecognized options and arguments
338 # are passed through to the 'git diff' command.
339 my %opts = (
340 difftool_cmd => undef,
341 dirdiff => undef,
342 extcmd => undef,
343 gui => undef,
344 help => undef,
345 prompt => undef,
346 symlinks => $^O ne 'cygwin' &&
347 $^O ne 'MSWin32' && $^O ne 'msys',
348 tool_help => undef,
350 GetOptions('g|gui!' => \$opts{gui},
351 'd|dir-diff' => \$opts{dirdiff},
352 'h' => \$opts{help},
353 'prompt!' => \$opts{prompt},
354 'y' => sub { $opts{prompt} = 0; },
355 'symlinks' => \$opts{symlinks},
356 'no-symlinks' => sub { $opts{symlinks} = 0; },
357 't|tool:s' => \$opts{difftool_cmd},
358 'tool-help' => \$opts{tool_help},
359 'x|extcmd:s' => \$opts{extcmd});
361 if (defined($opts{help})) {
362 usage(0);
364 if (defined($opts{tool_help})) {
365 print_tool_help();
367 if (defined($opts{difftool_cmd})) {
368 if (length($opts{difftool_cmd}) > 0) {
369 $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
370 } else {
371 print "No <tool> given for --tool=<tool>\n";
372 usage(1);
375 if (defined($opts{extcmd})) {
376 if (length($opts{extcmd}) > 0) {
377 $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
378 } else {
379 print "No <cmd> given for --extcmd=<cmd>\n";
380 usage(1);
383 if ($opts{gui}) {
384 my $guitool = Git::config('diff.guitool');
385 if (defined($guitool) && length($guitool) > 0) {
386 $ENV{GIT_DIFF_TOOL} = $guitool;
390 # In directory diff mode, 'git-difftool--helper' is called once
391 # to compare the a/b directories. In file diff mode, 'git diff'
392 # will invoke a separate instance of 'git-difftool--helper' for
393 # each file that changed.
394 if (defined($opts{dirdiff})) {
395 dir_diff($opts{extcmd}, $opts{symlinks});
396 } else {
397 file_diff($opts{prompt});
401 sub dir_diff
403 my ($extcmd, $symlinks) = @_;
404 my $rc;
405 my $error = 0;
406 my $repo = Git->repository();
407 my $workdir = find_worktree();
408 my ($a, $b, $tmpdir, @worktree) =
409 setup_dir_diff($repo, $workdir, $symlinks);
411 if (defined($extcmd)) {
412 $rc = system($extcmd, $a, $b);
413 } else {
414 $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
415 $rc = system('git', 'difftool--helper', $a, $b);
417 # If the diff including working copy files and those
418 # files were modified during the diff, then the changes
419 # should be copied back to the working tree.
420 # Do not copy back files when symlinks are used and the
421 # external tool did not replace the original link with a file.
423 # These hashes are loaded lazily since they aren't needed
424 # in the common case of --symlinks and the difftool updating
425 # files through the symlink.
426 my %wt_modified;
427 my %tmp_modified;
428 my $indices_loaded = 0;
430 for my $file (@worktree) {
431 next if $symlinks && -l "$b/$file";
432 next if ! -f "$b/$file";
434 if (!$indices_loaded) {
435 %wt_modified = changed_files($repo->repo_path(),
436 "$tmpdir/wtindex", "$workdir");
437 %tmp_modified = changed_files($repo->repo_path(),
438 "$tmpdir/wtindex", "$b");
439 $indices_loaded = 1;
442 if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
443 my $errmsg = "warning: Both files modified: ";
444 $errmsg .= "'$workdir/$file' and '$b/$file'.\n";
445 $errmsg .= "warning: Working tree file has been left.\n";
446 $errmsg .= "warning:\n";
447 warn $errmsg;
448 $error = 1;
449 } elsif (exists $tmp_modified{$file}) {
450 my $mode = stat("$b/$file")->mode;
451 copy("$b/$file", "$workdir/$file") or
452 exit_cleanup($tmpdir, 1);
454 chmod($mode, "$workdir/$file") or
455 exit_cleanup($tmpdir, 1);
458 if ($error) {
459 warn "warning: Temporary files exist in '$tmpdir'.\n";
460 warn "warning: You may want to cleanup or recover these.\n";
461 exit(1);
462 } else {
463 exit_cleanup($tmpdir, $rc);
467 sub file_diff
469 my ($prompt) = @_;
471 if (defined($prompt)) {
472 if ($prompt) {
473 $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
474 } else {
475 $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
479 $ENV{GIT_PAGER} = '';
480 $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
482 # ActiveState Perl for Win32 does not implement POSIX semantics of
483 # exec* system call. It just spawns the given executable and finishes
484 # the starting program, exiting with code 0.
485 # system will at least catch the errors returned by git diff,
486 # allowing the caller of git difftool better handling of failures.
487 my $rc = system('git', 'diff', @ARGV);
488 exit($rc | ($rc >> 8));
491 main();